Polyalkylene polyamino acids



Patented Mar. 23, 1954 UNITED STATES PATENT OFFICE POLYALKYLENEPOLYAMINO ACIDS Frederick C. Bersworth, Framingham Center, Mass.

No Drawing. Application June 3, 1952, Serial No. 291,578

8 Claims.

wherein Y is a bivalent alkylene group containing from 2 to 3 carbonatoms; X is a bilvalent alkylene group containing from 4 to 12 carbonatoms which may be interrupted by ether oxygen atoms; Z is a bivalentalkylene group containing from 2 to 6 carbon atoms which may be eitherstraight chained or branched; and A is one of the groups consisting ofCH2'COOH;

CHz-CHz-COOI-I; CH2-PO(OH) 2,

CH2-CH2-PO(OI-I) 2, CH2'CH2SO3H and the alkall metal and ammonium saltsthereof.

A further object is to provide a new type of polyalkylene polyamino acidmetal ion chelating agents that contain independently reactive tertiaryamino nitrogens.

Still another object is to provide a, dual functioning metal ionchelating agent.

Other objects will be apparent as the invention is more fullyhereinafter disclosed.

In accordance with these objects I have discovered that when an alkylenepolyamino acid contains at least four amino nitrogens spaced apart byalkylene groups, the chemical activity of the compound is markedlychanged by varying the number of carbon atoms in the spacing alkylenegroups. I have found that when the alkylene group between two of theinner amino nitrogens contains from 2 to 3 carbon atoms and the alkylenegroup spacing the other amino nitrogens from the two spaced inner aminonitrogens contains at least four but not over 12 carbon atoms,

the two inner spaced amino groups are reactive as diamines and the endspaced amino nitrogens react chemically as tertiary nitrogensindependently of the diamine reactive inner amino groups.

Based on this discovery I have formed the polyalkylene polyamino acidsconforming to the above generic formula in which the A groups attachedto the two inner spaced nitrogens function chemically as metal ionchelating groups and the end amino nitrogens are capable of independentchemical reaction with mineral and fatty acids as tertiary nitrogens toform acid salts therewith, many of which are of great utility in theart.

The independent chemical activity of the compounds of the presentinvention may be best illustrated by the following formula, using theacetic derivatives of the amino acid as a specific example:

This diacetic amino acid will react with a divalent metal ion to form achelate compound conforming to the following structure:

The end hydroxy-amino nitrogen groups, however, are separately andindependently reactive chemically with mineral and fatty acids usingstearic acid as an example, to form compounds of the followingstructure:

The compound of Formula 3 is essentially a polyalkylene polyamino acidsoap compound which in aqueous solution functions as a one-- latingcompound substantially as indicated in Formula 2. The carboxylic acidgroups of this fatty acid compound may be neutralized by alkali metaland ammonium ions without inter- For the purpose of this invention, thelimitamy U. S. Patent No. 2,407,645, issued Septemtions imposed upon thevarious alternative ber 1'7, 1946-. values of X, Y, Z and A are notarbitrarily Another method which may be employed to selected. On thecontrary, bearing in mind that produce the compounds of this inventionconthe preferred compounds of this invention are sists in reacting onemolecular proportion of the designed to contain a plurality of spacedamino proper symmetrical alkylene diamine dialkyl nitrogen groups, thespacing between two of phosphonic or sulfonic or dialkanoic acid, suchthe interior nitrOgens being that I imparting as N,Nethylene diaminediacetic acid, with two thereto the chemical'reactivity of a diamine,and molecular proportions of a suitable halogen subthe spacing betweenthese interior nitrogens and stituted alkyl dialkanolamine, for example,the end nitrogens being that imparting to theN-(e-chlorobutyl)-diethanolamine under condinitrogen atoms thereof thechemical reactivity tions such as to insure a substantial yield of of atertiary nitrogen independently of the inthe desired product. Thismethod is well suited terior nitrogen atoms, thereby adapting the forthe introduction of the -CH2CH2COOM the compound to act as sequesteringagents pargroup since other methods, for example, the ticuarly in thechelating of heavy metal ions, action of chloropropionic acid and itssalts upon and, more particularly, to serve as intermediates thepolyalkylol polyalkylene polyamines tend to in further syntheses basedon the tertiary form ether type acids.

chemical activity of the end amino nitrogens, The CH2CH2COOM group mayalso be inthese limitations are of the essence of the present troducedby cyanoethylation of the proper polyinvention; alkylol polyalkylenepolyamine followed by hy- "In. order-to permit the independent functiondrolysis of the resulting dipropi'onitrile derivaof the nitrogen atoms.inzthe end amino groups tive.

as tertiary nitrcgens the X groups spacing these Still another method ofpreparation comprises amino groups from the interior diamine reacting inreacting one molecular proportion of a, symnitrogens must contain atleast four carbon metrically substituted halogen alkyl or alkoxyatoms.To obtain maximum sequestering abilalkyl diamine dialganoic acid (orcorresponding ity, for heavy metal ions, the Y group spacing dialkylphosphonic or sulfonic acid) or its althe interior diaminereactingnitrogensmust conkali metal salts, for example, N,N-di-(2chlorota-in notless than two nor more than three ethoxyethyD-ethylene diamine diaceticacid, carbon atoms, and the Agroups of the comwith two molecularproportions of an appropound must be either CH2 COOM or priatedialkanolamine, such as, diethanolamine. -CI I2CH2COOM to allow theformation of 5 or Although these compounds can be prepared 6 memberedrings during sequestration. Adeby methods other than those describedabove quate water solubility is a desirable but not a and also bymodifications which will appear to necessary property for thesecompounds. Other those skilled in the art, I prefer to use the prothingsbeing equal, with increase in the size and cedures followed in thespecific examples hereinweight of the various radicals X, Y and Z theafter given since they are easily carried out, rewater solubilty of thepolyalkylol polyalkylene quire no complicated apparatus and involve apoly'amino acids decreases; Limits therefore minimum of manipulativesteps.

must be set for the sizes of these various radicals 40 In order tounderstand this invention more and these-limits 'must vary withvariations in clearly the following examples are given: the nature ofthe radicals. The presence of the solubilizing hydroxyl and carboxylgroups in the EXAMPI I compounds, however, permits a wide variation 0118mol o N, Y-

in the f mf f Y and Z before ethyl) --ethylen diamine was treatedaccording Water solubility 1s dimimshedto an undesirable to my UI SIPatent NQI 1407545 issued Septem extent. Similarly, if the X groupspossess an her lqI 1946I This methodI briefly, comprises h linkage, h ycan b of greater S and adding two mole of formaldehyde and two mols w lthanqf they a l r m of sodium cyanide slowly and in small balanced5.61185 of T? t m.. p 9?" quantities under strongly alkaline conditionsto sist of phosphonic and sulfonic acids vary simithe diamine andheat-mg the mixture with rapid larly in their physical properties withvariation agitation Evaporation of the reaction mixture m the S129 andtype of X and l'admals Present gave a pale viscid mass consisting of thedisodium therein. I I I I I salt ofN,N,-di-(2-iminodiethanol-ethoxyethyl)- Th c p n of l mven n ar obmethylene diamine diacetic acid. having the able by any of several knownmethods, for exformula:

CH2-CH2OH '7 CH1CH:OH I I |I -OH2CHa-O-CH-CHzlYT-CHOHzNCH OHzO-CHnCH:-Il' I oils-onion CIlHa CH3 ore-onion OOQNe (500m ample, conversion of theappropriate polyalkylol EXAMPLE II polyalkylene polyamines of thegeneral formula:

' To 0.1 mol of the disodium salt of N,N'-ethyl- H ene diaminedipropionic acid in 100 ml. of water NnxnNqgnNnxnNI II I at slow refluxthere was added over a two hour HO; I period 0.2 mol of4-bromobutyldiethanolamine.

I I I II I I I I The mixture was heated at gentle reflux for an preparedaccording to my copending application additional four hours.

Serial No. 291,5?7 filed-June 1952, to'the di- Evaporation of theaqueous solution to dryness acetic acid derivative by the process setforth in under reduced pressure gave a Dale yellow viscous liquidsoluble in hot alcohol consisting of the compound N,N'-di (4iminodiethanolbutyD- ethylene diamine dipropionic acid having thefollowing formula:

HOCH2-CH2 OHl-CHIOH N-(CH2)4NCHaCH:N(CHz)4-N HO CHz-CH: CH2 H: CHa-CHaOH1H: 3H: 30 OH )0 OH EXANEPLE III 0.1 mol of N.N'-di-(8-iminodibutanol-octy1) CHPCHQOH Hl-CHiOH isopropylene diamine wastreated according to my U. S. Patent No. 2,407,645, issued September 17,1946. Evaporation of the reaction mixture to dryness under reducedpressure gave a viscid yel- 2 low product consisting of the disodiumsalt of N ,N'-di-(8-iminodibutanol-octyl) isopropylene diamine diaceticacid having the formula:

Its aqueous solution sequesters heavy metal ions over a wide pH rangeand is compatible with soap.

EXAMPLE IV To 0.1 mol of the disodium salt of N,N'-ethylene diaminedipropionic acid in 100 ml. of water there was added over a four-hourperiod 0.2 mol of N-(2-chlor0ethoxyethyl) diethanolamine. The mixturewas refluxed for an additional four-hour period after which time it wasevaporated to dryness under reduced pressure. Repeated alcoholextraction of the residue followed by evaporation of the alcohol gave anextremely viscous yellow oil consisting of the compoundN,N'-di-(2-iminodiethanolethoxyethyl)-ethylene diamine dipropionic acidhaving the formula:

one-onion CH; CHs-CHaOH EXALEPLE VII To a gently refluxing solution of0.5 mol of N,N-di(S-iminodibutanol-octyl) -isopropylene di- 5 amine in500 ml. of alcohol containing 1.0 mol of sodium hydroxide there wasadded gradually over two hours, 1.0 mol of chloroethyl sulfonic acid.After four hours of refluxing, the sodium chloride was removed byfiltration and the alcohol by distillation. The viscid yellow residueconsisting of the compound N ,N'-di- (8-iminodibutanol-octyl)isopropylene diamine-diethyl sulfonic acid is soluble in Water andalcohols and has the formula:

The following symmetrical alkylene diamine dialkanoic dialkyl phosphonicand dialkyl sulfonic acids and their alkali metal salts exemplify theclass of starting materials useful for making the compounds of thisinvention: N,N'-isopropylene diamine diacetic acid and its alkali metalsalts, N ,N-ethylene diamine diacetic acid and its alkali metal salts,N,N-trimethylene diamine diacetic acid and its alkali metal salts,N,N'-ethyl- D ene diamine dipropionic acid and its alkali metalCHr-CHzOH 0.2 mol of N,N-di-(4-iminodiethanol-butyl)- isopropylenediamine was treated accordin to my U. S. Patent No. 2,407,645, issuedSeptember 17, 1946. Evaporation of the reaction mixture to dryness gavea yellow solid consisting of the disodium salt ofN,N'-di(4-imino-diethanol-butyl) -isopropylene diamine diacetic acidhaving the formula:

salts, N,N-isopropylene diamine dipropionic acid and its alkali metalsalts, N,N-trimethylene di-J amine dipropionic acid and its alkali metalsalts, N,N-ethylene diamine dimethyl phosphonic acid, N,N-ethylenediamine di-ethyl phosphonic acid, N,N'-isopropylene diamine di-propylphosphonic acid, N,N'-trimethylene diamine di-ethyl phosphonic acid,NAT-ethylene diamine diethyl sulfonic acid and N,N-isopropylene diaminediethyl sulfonic acid.

As suitable halogen substituted alkyl or alkoxyl alkyl dialkanolaminesthe following compounds may be employed; N-(Z-chloroethoxyethyl)diethanolamine, N (3-chloropropoxyethyl) diethanolamine, N G-bromohexyl)-diisopropanolamine, N- (4-chlorobutoxyethyl) -diisopropanolamine,N-(-chlorobutyl) -diethanolamine;, N'-

(omega-dodecyl) diethanolamine and N (4- chlorobutyl) -dipropanolamine,and the corresponding bromo compounds thereof. 7 V

Suitable'halogenated alkyl phosphonic acid to be employed arechloromethyl phosphonic acid. chloroethyl phosphonic acid, chloropropylphosphonic acid and their methyl and ethyl esters. A suitablehalogenated alkyl sulfonic acid, for example, is chloroethyl sulfonicacid or its alkali metal salts.

As will be seen from the above disclosure the 10 ousfiollltifm P the p yp y y t 1 17- new compounds herein disclosed may be made m acld 1n erelatlve molar proportwns from the, following starting materials;namely, (healed and healing P soljdtlon complete polyalkylolpolyalkylene polyamines, having the matlqn 0f the soap'hke ammo {401dcompound; t t It is well known that a serious allergy exists in manypeople toward soaps. Neutral soaps have been recommended but soapshaving a pH below 10.5 are not satisfactory detergents. These Isoap-like amino acid compounds are water soluble symmetrical alkylenediamine dialkanoic acids or and of near neutral pH, possess excellent fa ing their alkali metal salts; and halogen substituted 20 action evenin the presence of heavy metal ions alkyl or alkoxy alkyldialkanolamines. and overcome the necessity of a high pH with its Thepolyalkylol polyalkylene polyamines suit- Subsequent in fi 't andgenerally 31.3mm able as starting materials for the new compounds toxicinclude the following: N,l-T-di-(2-iminodietha- The compounds of thepresent invention are, nolfethoxyethyl)ethylene diamine f useful also inthe leather and textile industries, ie e d w l ethoiyetilyb isopropylenein cosmetic and soap compositions, polishes, glass ammei N f Q Y P Q'and metal cleaning preparations, as antioxidants, tnmethyleee (hammer d1(3 f Q as additives to lubricants and in numerous other ethanolisopropyloxyethyl) ethylene diamine, applications for which metal ionchelating and d1 f lmlnodlethanol butyloxyethyl) sequestering agentsgenerally heretofore have ethylene diam1ne, N,N- (ii-(4iminodiethanolbeen monly employed.

PPW 3 diemine, d1 Having hereinabove disclosed the present inel q r PP'Q Z Y vention generically and specifically and having dlamme and (Omegalmmodwthanol- I 7 given a plurality of specific examples to illustratedodlacyl) dlammethe same, it is believed apparent that the inven- In fthe aufyenefllammes alkyl' tion may bewidely modified without essentialde-' e f dlalkanolc aclds F salts parture therefrom, and all suchmodifications and mentloned above compounds 15mg LZ'dmmmO' adaptationsof the invention are contemplated as cyclohexame LZ'dIammOCYOMhEXane, N"may fall within the scope of the following claims. diacetic acid or itssalts may be used. 7 40 What I Claim A preferred compound of this seriesis produced 1. Chemical compounds corresponding to the from1,2-diaminocyclohexane and N-(e-chlorogeneral formula; butyl)-diethanolamine and then by conversion of the polyalkylol polyalkylenepolyamine derivative N X to the diacetic acid derivative by the processas set forth in my U. S. Patent No. 2,407,645, issued A A ZmOHVSeptember 1946, a d is p ted by the V wherein Y is a bivalent alkyleneradical of" two following formula: to three carbon atoms selected fromthe group OONa COONa activity of the tertiary nitrogens and have, therefore, many diverse applications. As indicated above, the most importantnew chemical property of these compounds is that they may serve as;intermediates in I the production of soap-like amino acid chelatingcompounds of the general These soap-like amino acid. compounds arereadily formed by adding a fatty acid to an aqueconsisting ofunsubstituted and substituted alkylene radicals containing at least onealkyl group; X is a bivalent alkylene radical of four to twelve carbonatomsselected. from the group consisting of unsubstituted andsubstituted bisisting of straight chained and branched chained radicals;A is a member of the group consisting CH2'CH2-PO(OH)2, CH2-CH2'SO3H andtheir,

ammoniumandalkali metal salts.

2. The compound N,N"-di-(Z-iminodiethanolethoxyethyD-ethylene diaminediacetic acid' conforming to the formula:

3. The compound N,N -di- (4-iminodiethano1- 6. The compound N,N'-di-(4-imino-diethano1- butyl) -ethylene diamine dipropionic acidconbutyl) -isopropy1ene diamine diacetic acid havforming to the formula:ing the formula: EOCHTCE CHTCHOH Ito-01120112 CH3 omomon 10011 (IJOOH 4.The compound N,N-di-(B-iminodibutanol- 7. The compound having theformula:

CH2-CH2OH CHz-CH2OH NCH2-CH2-O-CH2-CHn-NCHzCH2N-CH2-CH2-O-CH:'CH2NCHz-CHzOH H2 (I311: C IHzCHaOH 5 $H2 CH2 O=I I =0 01 \OH ofi \OH octyl)isopropy1ene diamine diacetic acid con- 8. The compound having theformula: forming to the formula:

HO-(CH2)| CH2)4-OH HO(OHI)4 (CHnM-OH N-(OH1)rN-CHz-GHz-N-(CHah-N 30)l-N*C m-o Hr-N-( 0 Han-N HO-(CHsh H: CH: (0H2)40H HO'(CHB)6 CH1 H9CH11)4OH COOH OOH H: OH; 5. The compound N,N'-di-(2-iminodiethanol-$0.11 $0.11 ethoxyethyl) -ethylene diamine dipropionic acid having theformula:

om-cmon CHr-CHIOH N-CHrCHzOCH:GHaN-CH:CHa-N-CH2OHa-OCHr-GH:N

1114111103 H, (3H1 CHPCHIOH H! (EH3 $0011 $003 FREDERICK C. BERSWORTH.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,176,441 Ulrich et a1. Oct. 17, 1939 2,316,606 Loder et a!Apr. 13, 1943 2,316,636 Teeters Apr. 13, 1943 2,407,645 Bersworth Sept.17, 1946 2,413,856 Bersworth Jan. 7, 1947 2,428,353 Bersworth Oct. 7,1947 2,532,391 Bersworth Dec. 5, 1950 2,609,390 Bersworth 1- Sept. 2,1952

1. CHEMICAL COMPOUNDS CORRESPONDING TO THE GENERAL FORMULA: